The present invention relates to an improvement in a method of producing polyether type antibiotics in an industrial scale.
As polyether type antibiotic there have been known Monensin (Journal of American Chemical Society, Vo. 89, page 5757, 1967), X-206 (Chemical Communications, 927, 1971), Salinomycin (British Pat. No. 1,378,414), SY-1 substance (Japanese O.P.I. No. 86191/76), SY-2 substance (Japanese Patent Application No. 5762/77), 4-methylsalinomycin (A 28086 substance) (Japanese O.P.I. No. 9788/76), Lasalocid (Journal of American Chemical Society, Vol. 73, 5295, 1951), Dianemycin (Journal of Antibiotics, Vol. 22, page 161, 1969), Nigericin (Biochemical and Biophysical Research Communication, Vol. 33, page 29, 1968), A-204 A (Journal of American Chemical Society, Vol. 95, 3399, 1973) and the like, and among these, Salinomycin, 4-methylsalinomycin, SY-1, SY-2, SY-3, SY-4, SY-5, SY-6, SY-7 and SY-8 substance are called Salinomycin type antibiotics because they have the similar chemical structures.
In this invention, the term "salinomycins" means each compound, or any mixture of at least two compounds, selected from the group consisting of salinomycin, SY-1, SY-2, SY-3, SY-4, SY-5, SY-6 and the like.
The present inventors already found that salinomycin, SY-1 and SY-2 were produced in the culture of Streptomyces albus waxman and henrich No. 80614 strain (FERM-P. No. 419), and succeeded in isolating the antibiotics from the culture (British Pat. No. 1378414, Japanese Unexamined Patent Publication No. 86191/1976 and Japanese Patent Application No. 5762/1977).
The inventors continued the study and found that, when the above strain is cultured in the medium containing fatty acid or its precursor, it produces salinomycin, SY-1, and SY-2 in high yield, and also produces new compounds such as SY-3, SY-4, SY-5, SY-6, SY-7 and SY-8.
As described in said literatures, these are produced by culturing each antibiotic producing microorganism belonging to the genus of Streptomyces. However, the yield of each antibiotic produced by such known method is not always satisfactory.